(2S,3R)-tert-butyl 2-hydroxy-3-(N-benzyloxycarbonyl)-aminobutanoate

(2R,3S)-3-Methyl-1-[4-(2-trifluoromethyl-benzyloxy)-benzenesulfonyl]-piperazine-2-carboxylic acid tert-butyl ester

(2S,3R)-tert-Butyl 2-tert-butyldimethylsilyloxy-3-(N-benzyloxycarbonyl-N-methyl)aminobutanoate

(1S,2R)-2-(N-Benzyloxycarbonyl-N-methyl)amino-1-(tert-butoxycarbonyl)propyl-1-methanesulfonate

(2R,3S)-3-Methyl-1-[4-(quinolin-4-ylmethoxy)-benzenesulfonyl]-piperazine-2-carboxylic acid tert-butyl ester

(2R,3R)-3-Methyl-1-[4-(2-trifluoromethyl-benzyloxy)-benzenesulfonyl]-aziridine-2-carboxylic acid tert-butyl ester

(2R,3S)-3-Methyl-1-[4-(2-methyl-benzyloxy)-benzenesulfonyl]-piperazine-2-carboxylic acid tert-butyl ester

(2R,3R)-1-[4-(Isoquinolin-4-ylmethoxy)-benzenesulfonyl]-3-methyl-aziridine-2-carboxylic acid tert-butyl ester

(2R,3R)-1-[4-(2-Ethyl-benzyloxy)-benzenesulfonyl]-3-methyl-aziridine-2-carboxylic acid tert-butyl ester

(2R,3S)-2-[4-(2-Ethyl-benzyloxy)-benzenesulfonylamino]-3-(2-hydroxy-ethylamino)-butyric acid tert-butyl ester

(2R,3R)-3-Methyl-1-[4-(2-methyl-benzyloxy)-benzenesulfonyl]-aziridine-2-carboxylic acid tert-butyl ester

(2R,3R)-2-Azido-3-benzyloxycarbonylamino-butyric acid tert-butyl ester

(2R,3S)-3-Azido-2-benzyloxycarbonylamino-butyric acid tert-butyl ester

(2R,3S)-3-(2-Hydroxy-ethylamino)-2-[4-(2-trifluoromethyl-benzyloxy)-benzenesulfonylamino]-butyric acid tert-butyl ester

(2R,3S)-4-Acetyl-1-[4-(5-fluoro-2-methyl-benzyloxy)-benzenesulfonyl]-3-methyl-piperazine-2-carboxylic acid tert-butyl ester

(2R,3S)-4-Acetyl-3-methyl-1-[4-(2-methyl-benzyloxy)-benzenesulfonyl]-piperazine-2-carboxylic acid tert-butyl ester

tert-butyl (2S,3R)-2-methanesulfonyloxy-3-[(tert-butoxycarbonyl)amino]butanoate

(2R,3S)-4-Acetyl-3-methyl-1-[4-(2-trifluoromethyl-benzyloxy)-benzenesulfonyl]-piperazine-2-carboxylic acid tert-butyl ester

(2R,3S)-2-[4-(4-Fluoro-benzyloxy)-benzenesulfonylamino]-3-(2-hydroxy-ethylamino)-butyric acid tert-butyl ester